Concrete block and method



(No Model.)

C. RICHARDSON CONCRETE BLOCK AND METHOD OF MAKING THE SAME.

Patented Cot vwamlfoz 2% tmaoseo STATES CONCRETE BLOCK AND METHOD OF MAKlNG THE SAME-I.

SPECIFICATION-forming part of Letters Patent No. QGLBSO, dated October 27, 1891.

Application filedOetober 16. 1889.

To all whom it may concern:

Be t known that I. GEORGE RICHARDSON, a clt inen of the United States, residing at Vi asn ngton, in the District of Columbia, have invented certain new and useful Improvements in Concrete Blocks and Processes of Making the Same; and] do herebv declare the following to be a full, clear, aiul exact description of the invention, such will en- TO able others skilled in the art to which it appertains to make and use the same.

My invention relatesto tiles, bricks, pa ing and building blocks, or similar blocks composed of concrete or a mixture of sand 1 and cement of two or more grades or qualities, and also to the process of making the same; and its objectis to so combine orunite the different grades orlayers in a mold of any desired shape that they will form a single homogeneous mass with the port ion suhj ected to Wear oi. a finer quality of cement mixture than the interior of the block. i

In order that my improved. process and the construction of the block may be more elearl y understood, I have illust ated in th accompanying drawings one form of mold which i have used with practical success. Figure 1 represents a vertical cross-sec tional perspective of my improved block. Fig. 2 shows a cross-section ol' a mold and lining-for molding the interior of the block. Fig. 3 is a vertical section of a mold with the lining removed, showing" the interior or coarse grade of the block in elevation. Fig. l a vertical section of a mold, showing the two grades of concrete mixture therein and the mold provided with a cover-plate. Fig. 5 represents a section'of the lining.

In carrying out my invention any suitable as mold may be used without departing from the principle thereof; but I prefer to employ a mold suostantially like the one shown in the drawings, in which A indicates the mold proper, Whichconsistsoi a casing open at top 5 and bottom and of any desired shape, according to the shape of block desired. At the bottom of the mold is an iawardly-projocling rib (1, upon which rests a removable plate a, forming the bottom of the mold. Resting upon this plate is a lining l3,alsoopen at top and bottom and of greater thickness at the top than at the bottom, the inner surface of Ollillg'dlitbll to more thoroughly saint no, 327,156. on model.)

which isprovided with dovetailed ribs or projections 0, increasing in width toward the botlom,.and at the top of the'lining i3 is an. inwardly-projecting flange b also formed with ribs b on its under side. and lilting within. the space between the flange is a movable plate b provided with ribs on its under side, though I may dispense with this plate,if die sired. To the top of the mold is secured a removable perforated cover-plate 0, having a funnel-shaped mouth 0. i

After placingthe lining,- l; in the mold A.,as shown in Fig. 2, I prepare two separate mixtnres of sandand cement,the eoarserof which I place in the mold Ainside the lining l5 and pack the same therein until the spaces be-- tween the ribs or projections bare filled and the mass is firm enough to retain its shape, '\'\ll( ll the plate I) is pressed down on the mass to form the-Toughened uyper surface. I then remove the lining l3 and the plate b when the coarse mixture will appear, as shown in Fig; 3, with the dovetail grooves and ribs on its heveleclsides and short ribs and grooves on its u pper sin-face corresponding to the projections on the mold, andbefore the mixture has time to set I fill the cavity or space left by" the lining B with the finer quality of the mixture, which enters the grooves in the coarse interior mixture and firmly unites therewith. The cover-plate O isthen placed on the mold and firmly clamped thereto, after which the mold anrl'contents are subjected to a vertically and horizontally reciprocating motion on a machine provided for the purpose for a sufticient length. of time to force or drive out all the air-spaces and superfluous waterfront the mixture. This jarring motion on also serves to more thoroughly'unite the two grades of mixtures. After the cover removed and before the cement- Tnas set I sprinkle or cover the mixture in the mold witlra dry mixture of cement and sand. to 5 take up any surplus water that may still remain in the mixture, after which the upper surface of the mixture is rubbed with a smoothlug-board or trowel, which gives a smoothefltnd harder surface to the bloelt :00 than it' this dry coating was not used.

After the mixture has set in the mold it is removed and subjected to any desired herdharden the cement for the outer coating and one part of be found that they have so thoroughly united of the block in the manner above described which is to form the coating.

v colors other same; but I prefer to subject it to the action of cool carbonieaid gas and watery va por.

In case it is desired to furnish blocks of than that of the natural color of the mixture, I add the coloring matter to the! mixture while the same is being prepared. The mixture I prefer to use for paving,- block is composed of equal parts of sand and cement to three pails of sand fortho interior of member; but these proportions may be greatly varied, as well as the ingred ien ts, wi.t;h-, outd'ep'arting from the principle of my invention. For instance, for the interior of the block I may use cement, sand, and gravel, or cement and finegravel' or broken stone.

After the concrete mixtures have set it will that "it will be impossible to separate them, and thevflblock will not be affected by change of temperature, as is often the case with blocks composed of different grades of material molded with one layer above the other.

In case it is desired to furnish a colored block of uniform quality I mold the interior more grades 'or mixtures, one of which is formed with dovetailed grooved surfaces and the other mixture formingthe coating united i eeneeo therewith before the mixtureshave set, substantially as and for the purposes described.

3. The method herein described 0t. making concrete blocks,which consists in placingin the mold a lifting, filling the spacewithin the same with a coarse concrete mixture, removing said lining, and filling, the Sl'Ml-CBiOP-llltl by the lining with a line concrete mixture, substantially as. and for the purposes de-; scribed. J

4. The method herein described of making concrete blocks, which consists in placing in the'mold a lining,-subsl-antialiy as described,

'havin a rib on its-innersidc filling'the siacc within the same with coarse concrete, removing the lining and filling the space, formed thereby with a fine concrete mixture, and finally subjecting the mold and contents to a jarring motion to firmly unite the two mix tures before they have set, substantially as and for the purposes described.

5. The method herein described of making concrete blocks, which consists in placing in the i'nold a lining having ribs on its inner side, filling the spaee'within the same with a coarse concrete, removing the lining and tilling the space formed thereby with a lineconerete mixture, subjecting the mold and com tents to a jarring motion, tofi'rnrly unite the two mixtures before they have set, and linall'y subjecting-the blocktothe action of carbonic acid gas and water or the vapors thereof, substantially as and'for the purposes (IOSCl'lbctl.

In testimony whereof I aflix my signature in presence of two witnesses.

GEORGE lll( llAltl)s()N.

Witnesses:

Eu'ii. WALKER, l:. W. Rrr'rnn, Jr.

but 

